/Engine/Source/Editor/UnrealEd/Classes/Editor/EditorEngine.h
This should only ever be called for a EditorEngine.
virtual [UWorld](API\Runtime\Engine\Engine\UWorld) * CreatePIEWorldByDuplication ( [FWorldContext](API\Runtime\Engine\Engine\FWorldContext) & Context, [UWorld](API\Runtime\Engine\Engine\UWorld) * InWorld, [FString](API\Runtime\Core\Containers\FString) & PlayWorldMapName )